Test Pulse Duration Parameter; Pre-Evaluation Parameter - WAGO 8FDI 24V PROFIsafe 750-662/000-004 Manual

62 Commissioning
7.3.5.3

Test Pulse Duration Parameter

Configuring the test pulse duration changes the safety response time
If you change the Test Pulse Duration parameter, then the safety response time
also changes. You can read more about this in section "Safety Response Time."
The Test Pulse Duration parameter is used to set the duration of the test pulses
for the short circuit test.
The test pulse duration applies equally to the test pulses at clock outputs T1 and
T2. However, if the short circuit test of all input channels assigned to a clock
output is deactivated, then the clock output in question is switched off (see
sections "Commissioning" > ... > "Short Circuit Test Ix Parameter" and
"Emergency Stop Connection, Single-Channel"). In this case, the Test Pulse
Duration parameter has no effect on the clock output in question, and the
parameterized value is irrelevant.
The correct test pulse duration setting depends on the capacitance of the input
wiring, which is influenced by the type of sensor connected and the cable length.
A higher capacitance of the wiring requires a longer test pulse duration. If the
wiring is fault-free but the F I/O module detects a short circuit of an input to an
external voltage, then the test pulse duration setting is not sufficient, and a larger
value must be selected.
7.3.5.4

Pre-Evaluation Parameter

The Pre-Evaluation parameter is used to switch dual-channel pre-evaluation of
the digital inputs on and off. You can set the parameter to the values "Single-
channel," "Equivalent" or "Antivalent."
With the "Single-Channel" setting, dual-channel pre-evaluation is deactivated.
With the "Equivalent" or "Antivalent" setting, the F I/O module combines the
corresponding digital inputs Ix and Ix+1 into one channel pair. Each channel pair
determines a logical channel pair value from its two physical channel values. The
signal states of the digital inputs are analyzed based on the rule setting using the
Pre-Evaluation parameter and applied to the process image as a logical channel
pair value as a 0-signal or 1-signal.
Depending on the value of the Pre-Evaluation parameter, the signal states of the
Ix and Ix+1 inputs are analyzed, reproduced in the process image and transferred
to the safe PLC differently.
If the Pre-Evaluation parameter is set to the "Equivalent" or "Antivalent" value,
then the same process value is transmitted to the safe controller for both
channels of the channel pair according to the pre-evaluation.
Manual
Version 1.0.0, valid from HW/SW Version 01/01
WAGO I/O System
750-662/000-004 8FDI 24V PROFIsafe